NO及NOS在低氧大鼠肺组织和主动脉中的差异性及其意义  

Alteration of nitric oxide and nitric oxide synthase in lung and aorta in hypoxic pulmonary hypertensive rats

作　　者：栾丽丽[1] 李志超[1] 黄玉芳[1] 董明清[1] 张博[1] 董海莹[1] 彭利静[1] 

机构地区：[1]第四军医大学病理生理学教研室,陕西西安710032

出　　处：《心脏杂志》2007年第3期258-261,共4页Chinese Heart Journal

摘　　要：目的观察低氧性肺动脉高压大鼠肺组织匀浆、主动脉匀浆及出肺血和入肺血中一氧化氮(NO)的含量、一氧化氮合酶(NOS)的活性。方法将24只雄性SD大鼠随机分成4组,即常氧2周组、常氧3周组、低氧2周组、低氧3周组。采用间断负压低氧法制备大鼠低氧性肺动脉高压模型;右心室导管法测定最高肺动脉压(PAP);左颈总动脉插管测量左颈总动脉压代表动脉血压(Psa);计算右心室肥厚指数[RV/(LV+S)];采用硝酸还原酶法测定各组大鼠出、入肺血及肺组织和主动脉匀浆中的NO含量;用化学比色法测定各组大鼠肺组织和主动脉匀浆中NOS的活性;应用免疫组化染色法观察各组大鼠肺组织及主动脉eNOS在蛋白质水平表达的变化。结果低氧组大鼠的PAP[(43.4±4.4)mmHg,(51.8±4.2)mmHg,1mmHg=0.133kPa],RV/(LV+S)(32.3±1.0,37.0±1.6)均高于其正常对照组[(20.8±2.4)mmHg,(21.8±3.9)mmHg;21.3±1.0,20.3±1.2,P<0.01)],且随缺氧时间延长而增高(P<0.01),而Psa与常氧对照组比无差别。低氧组大鼠的出、入肺血及肺组织匀浆中的NO含量、NOS活性及肺组织eNOS的表达量均较其常氧对照组显著降低(P<0.01),出肺血与入肺血的NO含量无差别;主动脉匀浆中NO含量和NOS的活性及大鼠主动脉的eNOS染色在各组间未见明显差异。结论低氧时,大鼠肺组织中NO的含量及NOS的活性均较常氧时降低,而主动脉中二者的表达在低氧和常氧时却没有差异,这种差异性可能是低氧时引起肺动脉高压却很少导致高血压的机制之一。AIM To observe the nitric oxide （NO） content and nitric oxide synthase （NOS） activity in lungs, aorta and blood from plasma of pulmonary artery （PA） and thoracic aorta （TA） in hypoxic pulmonary hypertension （HPH） rats. METHODS Twenty-four male SD rats were randomly divided into four groups with 6 rats in each group： normoxic 2 weeks group, normoxic 3 weeks group, hypoxic 2 weeks group and hypoxia 3 weeks group. The animal model of hypoxia pulmonary hypertension was established by intermittent hypoxia （ imitation of highland 5000 m）. The maximum pulmonary artery pressure （ PAP max） and system artery pressure （Psa） were measured by fight cardiac catheterization and by cannulating the left common carotid artery （LCCA）, respectively. The right ventricle （RV） and left ventricle plus septum （ LV ＋ S） of rats were weighed. The method of nitrate reductase was used to determine the chan- ges of NO and NOS activity in the plasma and tissue and immunohistochemistry was used to observe eNOS expression in pulmonary and aorta. RESULTS In the hypoxic groups, PAPmax [ （43.4 ± 4.4） mmHg, （51.8 ±4.2） mmHg] and the RV/（ LV ＋ S） （32.3 ±1.0, 37.0 ± 1.6） increased significantly compared with those in the control groups[ （20.8±2.4）mmHg, （21.8 ±3.9） mmHg, 21.3 ± 1.0, 20.3± 1.2, P 〈0.01 ]. The longer the time exposed to hypoxia, the higher these parameters （P 〈0.01 ）, but there was no difference in Psa between hypoxic groups and normoxic groups. NO content and NOS activity in lung homogenate, plasma of PA and TA in HPH rats decreased significantly compared with those in the correspondingly control group （P 〈0.01 ） and no difference was found in the NO content of PA and TA. No difference of the NOS activity was found in aorta homogenate among the four groups. The positive expression of eNOS in pulmonary decreased in hypoxic groups compared with that in the normoxic groups but no difference was found in aorta. CONCLUSION NO content and NOS activ

关 键 词：低氧性肺动脉高压 肺 主动脉 一氧化氮 一氧化氮合酶 

分 类 号：R363.2[医药卫生—病理学]